Solid polymers from oxazol-5-one and a bis-maleimide

ABSTRACT

Process for preparing a polymer which comprises reaction of A. an oxazol-5-one of formula   WHERE R and R1, which may be the same or different, each represent a hydrogen atom or an aliphatic, cycloaliphatic, aromatic, araliphatic, or heterocyclic group, free from ethylenic or acetylenic unsaturation, with B. a compound containing at least two ethylenic carbon-carbon bonds per molecule.

United States Patent Rigby et al.

154] SOLID POLYMERS FROM OXAZOL-S- ONE AND A BIS-MALEIMIDE [72]inventors: Colin William Rigby, Barley; Bernard Peter Stark, Cambridge,both $159.81? [73] Assignee: Ciba-Geigy AG, Basel, Switzerland...

[22] Filed: July 14, 1970 [21] Appl. No.: 62,739

[30] Foreign Application Priority Data July 22, 1969 Great Britain...36,905/69 [52] U.S. Cl. ....260/78 UA, 117/161 P, 117/161 UN, 260/30.8DS, 260/47 UA, 260/47 CZ,

260/63 N, 260/67.5, 260/78.4 R, 260/78.4 E

[51] Int. Cl. ..C08g 20/20 [58] Field of Search ..260/78 UA, 78 A, 47 UA[56] References Cited UNITED STATES PATENTS 3,216,974 11/1965 Van Gijzen..260/78 UA 3,355,518 11/1967 Sullivan et al ..260/78 UA 3,583,9506/1971 7 Kollinsky et a1. ..260/78 A [451 Sept. 26, 1972 PrimaryExaminer-Harold D. Anderson Attorney-Harry Goldsmith, Joseph G. Kolodnyand Mario A. Monaco ['57] ABSTRACT Process for preparing a polymer whichcomprises reaction of where R and R, which may be the same or different,

each represent a hydrogen atom or an aliphatic, ,cycloaliphatic,aromatic, araliphatic, or heterocyclic group, free from ethylenic oracetylenic unsaturation, 'with B. a compound containing at least twoethylenic carbon-carbon bonds per molecule.

4 Claims, No Drawings SOLID POLYMERS FROM OXAZOL-S-ONE AND ABIS-MALEIMIDE comprises reaction of A. an oxazol-5-one of formula whereR and R, which maybe the same or difi'erent, each represent a hydrogenatom or an aliphatic, cycloaliphatic, aromatic, araliphatic, orheterocyclic group, free from ethylenic or acetylenic unsaturation, withB. a compound containing at least two ethylenic carbon-carbon doublebonds per molecule.

R and R may, for example, individually represent an alkyl, cycloalkyl,aryl, or aralkyl group, each containing not more than ten carbon atoms,hydrogen, and optionally, chlorine. Further preferred are such oxazol-S-ones wherein at least one of R and R is an aryl group, particularly amonocyclic group such as a phenyl or tolyl (i.e., CH C l-l group.Especially preferred are 2-phenyl-4-benzyloxazol-5-one, and2,4-diphenyloxazol-S-one.

The ethylenic double bonds in the compound (B) are advantageously ofhigh dipolarophilic reactivity, i.e., at least one carbon atom in eachof two ethylenic double bonds bears an activating group such as a keto(which may be part of a ring to form a quinone), aldehyde, carboxylicacid, carboxylic ester, nitrile, acid anhydride, imide, or nitro group,and preferably the compound (B) contains not more than two ethylenicdouble bonds so activated.

Examples of suitable bisdipolarophiles (B) are bis(maleimides) offormula wherein R represents a divalent organic residue linked through acarbon atom or atoms thereof to the indicated nitrogen atoms, especiallyan alkylene or arylene hydrocarbon group which may be interrupted byoxygen, such as that having the formula Other suitable bisdipolarophiles(B) have the formula where X and X, which may be the same or different,each represent hydrogen, halogen, or an organic substituent, and Y andZ, together with the indicated carbon atoms, complete a carbocyclic ringwhich may be bridged by atoms or by chains of atoms, such as one or moreendoalkylene hydrocarbon groups each containing one to three carbonatoms and optionally chlorine, with the proviso that at least two of X,X, Y, and Z each represent or contain an activating group such as a keto(which may be part of a ring to form a quinone), aldehyde, carboxylicacid, carboxylic ester, nitrile, acid anhydride, imide, or nitro group.

Preferably at least one of the indicated ethylenic double bonds in thebisdipolarophiles of Formula III is present in a structure of formulaExamples of such bisdipolarophiles are compounds of formula H- H Q C J-OOOQ t. .lY

where Q represents an alkylene hydrocarbon chain which may beinterrupted by one or more ether oxygen atoms, more especially analkylene hydrocarbon group containing from three to five carbon atoms inthe chain, such as that formed with butane-1,4-diol; pbenzoquinone; andtetracyanoquinodimethan.

The polymer-forming reaction is accomplished by heating thebisdipolarophile (B) with the oxazol-S-one (A) fora time sufficient forthe polymer to form, usually at a temperature between 60C and C,preferably in an inert solvent such as xylene, toluene,N,N-dimethylformamide, ethyl acetate, or nitrobenzene, with eliminationof carbon dioxide. The specific heating temperature is not critical tothe invention process with the proviso that carbon dioxide is eliminatedwith formation of solid polymer. Preferably, approximately equimolaramounts of the reactants are employed, i.e., 0.8 to 1.2 mol of theoxazol-S-one (A) per mol of the bisdipolarophile (B).

The polymer products obtained by the process of this invention have veryhigh thermal stabilities, and may find use as coatings such as wireenamels and in ablation structures. These are formed by known methods,

for example as described by W. Grunsteidl, Kunststoffe, 58, 739 44(1968). The object to be coated, such as a wire is treated with asolution of A and B in a suitable solvent. The solvent is thenevaporated and the object heated to form the polymer on its surface.

It is believed, although the utility of this invention does not dependon the truth of this belief, that the polymer-forming reaction involvesthe sequence:

i. addition of the oxazol-S-one (A) in a 1,3-dipolar form such as thatshown in formula Ia g te ...L Bi, VI

Thus, the polymer obtained from an oxazol-S-one of Formula I and abis(maleimide') of formula II is considered to have a repeating unit offormula o o o o N/ NH \NRY o oo 1 VII The product from a cyclicbisdipolarophile (B) of Formula III and an oxazol-S-one (A) is ofespecial interest, as it is believed to have a ladder polymer structuresuch as shown in the formula Y X Y X I NE NH I E The very high thermal stibiut iifififiliaum supports this attribution of a ladder structure.

In Formula VI to VIII, R, R, X, X, Y, and Z have the meanings previouslyassigned, and n denotes an integer.

The following examples illustrate the invention.

sfls s lfiarssiysain d re s e ti de 1 .18

tions in the infra-red spectra of the polymeric products are recorded,the degree of absorption being indicated by w weak, m medium, s strong,v.s. very strong. The weight loss on heating was determined by means ofa Stanton Thermobalance programmed to effect a temperature rise of 6 perminute over the range 100 to l400.

In all cases the polymeric products did not melt at 300.

4-BenzyI-2-phenyloxazol-5-one (I,R=C H CH R C was prepared as describedby Goodman and Levine (J. Amer. Chem. Soc., 1964, 86, 2918). 2,4-Diphenyloxazol-S-one (I,R=R=C H was prepared in an analogous manner itmelted at l200 (from ether-hexane). The maleimides (II) employed wereobtained by the procedure given in United States Specification 2444536.Butane-1,4-diol cyclic difumarate (III, X=X -Z C(:O)O(CH OC(:O)) wasprepared from the diol and fumaryl chloride as described by Bailey andFeinberg in American Chemical Society Polymer Preprints, 8 (1), April1967. The preparation of tetracyanoquinodimethan (III, X=X H, Y=Z=C:C(CN) was described by Acker et al. in J. Amer. Chem. Soc.. 1960, 82,6408 and ibid, 1960, 84, 3370; the preparation ofdicyclopentadienedicarboxylic acid (IV, Q=Q'=H) was described by Weisein J. Org. Chem., 1967, 32, 3542.

EXAMPLE] Ethylenel ,2-bis(N-maleimideXILR -CH CH )(4.0g) and4-benzyl-2-phenyloxazol-5-one (I, R=C H CH R=C H (455g) were heated inrefluxing xylene (250 ml) overnight. A yellow precipitate appeared after1 hour, and after 12 hours the supernatant liquid had become almostcolorless. The xylene was decanted while still hot, the precipitate waswashed with more hot xylene, filtered off, washed with ether, and driedat 50 under a vacuum of 0.1 mm Hg. The polymer weighed 3.38 g (40percent yield); it was insoluble in all solvents tried.

Infra-red spectrum: 3040 (w), 1695 (v.s.), 1495 (w) 1395 (m), 1160 (m),690 (m) Weight loss (in air): 10% at 350, 20% at 385, 50%

at 500, complete at 680.

EXAMPLE II Bis(p-male imidophenyl)methane (9.3 g) and4-benzyl-2-phenyloxazol-5-one (6.4 g) were heated together in 400 ml ofxylene, and the VIII product isolated, as described in Example I exceptthat the polymer was dried at under a vacuum of 1 mm Hg. The polymerweighed 5.71 g (35% yield): it was sparingly soluble in dimethylsulphoxide.

Found: C, 74.4; H, 5.1; N, 6.8.(C H N OQ requires C, 76.4; H, 4.8; N,7.43%. Infra-red spectrum: 3000 (w), l760 (w), 1700 (s),

1505 (m), 1380 (m), 1170 (m) Weight loss (in air): 10% at 345, 20% at395, 50%

at 510, complete at 670.

EXAMPLE III Ethylene-1,2-bis(N-maleimide) (1.45 g) and 2,4- 5

diphenyloxazol-S-one (l,R==R =C l-l,) (1.56 g) were heated in 100 ml ofxylene, and the product isolated, as described in Example 1 except thatit was washed only with hot xylene and was dried at 170 and 1 mm Hg.

Yield: 0.89 g (37%) Infra-red spectrum: 3050 (w), 1750 (m), 1690 (s),

1495 (w), 1395 (s), 750 (m), 690 (s) Weight loss (in air): 10% at 340,20% at 395, 50%

at 520, complete at 620.

Y EXAMPLE IV A mixture of bis(p-maleimidophenyl)methane (3.14 g),2,4-diphenyloxazol-5-one (2.09 g). and 150 ml of xylene was heated underreflux for hours. The 20 product was isolated as described in Example111.

Yield: 2.23 g (45%) I Infra-red spectrum: 3040 (m), 1730 (m), 1690 (s),

1505 (m), 1390 (m), 680(m) I Weight loss (in air): 10%.at 350, 20% at405, 50%

at 500, complete at 630.

, Weight loss (in air): 10% at 265, 20% at 280, 50%

at 330, complete at 610.

7 7 EXAMPLE v1 2,4-Diphenyloxa2ol-5-one (1.15 g) andbis(pmaleimidophenyD methane (1.72 g) were heated at 120 in 200 ml ofN,N -dimethylformamide for 5 days. The hot mixture was poured into hotxylene, and the ,brown precipitate was filtered off, washed with hotxylene, and dried by heating at 70 under a vacuum of 0.2 mm Hg.

Yield: 1.2 g (40%) Infra-red spectrum: 3045 (m), 1690 (s), 1505 (m),

1380 (m), 1175 (m), 690 (m) Weight loss (in air): 10% at 340, 20% at420,

at 500, complete at 640.

EXAMPLE VII 4-Benzyl-2-phenyloxazol-5-one (0.73 g),tetracyanoquinodimethan (III, X=X'=I-I, Y=Z= C:C(CN) (0.61 g), and 250ml of ethyl acetate were heated to refluxing for 6 days. The brownprecipitate was filtered off and heated at 100 under a vacuum of 1 mmHg.

Yield: 0.76 g (62%) Infra-red spectrum: 3030 (m), 2025 (w), 2015 (m),

2010 (w), 1770 (m), 1736 (m), 1600 (s), 860 (m) Weight loss (in air):10% at 350, 20% at 370, 50%

at 550,- complete at 750.

EXAMPLE vm Tetracyanoquinodimethan (0.9 g), 2,4-diphenyloxazol-S-one (lg), and ethyl acetate (250 ml) were heated to reflux: the solutionimmediately turned green and then blue. After the mixture had beenheated to reflux for 6 days, the blue precipitate was filtered off andheated at under a vacuum of 0.1 mm Hg.

Yield: 0.95 g (54%) Infra-red spectrum: 3040 (m), 2015 (s), 1570 (s),

1500 (m), 1320 (s), 1770 (s), 820 (m) Weight-loss (in air): 10% at 340,20% at 370, 50%

at 430, complete at 650.

EXAMPLE IX 2,4-Diphenyloxaz'ol-5-one (0.45

bis(maleimido )benzene (II, R 2),

and xylene ml) were heated to reflux for 4 days. The brown precipitatewas filtered off, washed with hot xylene, and dried at 70 under a vacuumof 0.1 mm Hg.

Yield: 0.26 g (34%) Infra-red spectrum: 3030 (m), 1690 (s), 1500 (m),

1350 (m), 1170 (m), 740 (w), 680 (m) Weight loss (in air): 10% at 360,20% at 405, 50%

at 575, complete at 900.

EXAMPLE X The procedure described in Example IX was repeated, using 1.31g of 2,4-diphenyloxazol-5-one and 1.12 g ofdicyclopentadienedicarboxylic acid (IV, Q=Q=H) and heating the mixtureto reflux for 7 days.

Yield: 0.22 g (10%) Infra-red spectrum: 2090 (m), 1690 (s), 1390 (m),

690 (m) Weight loss (in nitrogen): 10% at 280, 20% at 980,

I EXAMPLE Xl 4-Benzyl-2-phenyloxazol-5-one (1.5 g) and 1.9 g of1,4-bis(maleimido)benzene in 200 ml of nitrobenzene were heated at -460for l8hours. The mixture was poured hot into hot xylene, and the brownprecipitate was filtered off and then dried by heating at 100 under avacuum of 0.1 mm Hg.

Yield: 0.80 g (41%) Infra-red spectrum: 3040 (m), 1700 (s), 1505 (s),

1350 (s), 1170 (s), 830 (m), 700 (s) Weight loss (in air): 10% at 380,20% at 410, 50%

at 500, complete at 840.

EXAMPLE XII 2,4-Diphenyloxazol-5-one (1.1 g) an p-benzoquinone (0.55 g)were heated at 150 in nitrobenzene for 4 days. The mixture was filteredhot, and the brown solid so obtained was heated at l50under a vacuum of0.1 mm Hg.

Yield: 0.20 g (20%) Infra-red spectrum: 3035 (m), 1590 (s), 1380 (m),

690 (m) Weight loss (in nitrogen): 10% at 310, 20% at 400,

50% at 1,000, 51.2% at 1,100.

What we claim is:

1. A solid polymer prepared by heating with elimination of carbondioxide A. an oxazol-S-one of formula where R represents a group of theformula at a ratio ofO.8 to 1.2 moles of (A) per mole of (B). 2. Thepolymer according to claim 1, wherein reactants A and B are heated at atemperature between 60 and 3. The polymer according to claim 1, whereinreactants (A) and (B) are heated in an inert solvent.

4. The solid polymer according to claim 1 prepared by heating (A) anoxazol-S-one of formula wherein R and R are each selected from the groupconsisting of hydrogen, phenyl, tolyl and benzyl, with (B) a compound ofthe formula where R represents a group of the formula at a ratio of0.8to 1.2 moles of(A) per mole of(B).

@2 3 2 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.359 5 417 2 Dated September 26, 1972 Inventor(s) Colin William Rigby etal It is certified that error appears in the above-ident'ified' patentand that said Letters Patent are hereby corrected as shown below:

Column 7 and Column 8, line 28 ineabh, delete "CH C HB I." endsubstitute CH C6H Signed and sealed this 16th day of April 1971i.-

(SEAL) Attest:

C. MARSHALL DANN Commissioner of Patents EDWARD M .FLETCHER JR AttestingOfficer

2. The polymer according to claim 1, wherein reactants A and B areheated at a temperature between 60* and 180*.
 3. The polymer accordingto claim 1, wherein reactants (A) and (B) are heated in an inertsolvent.
 4. The solid polymer according to claim 1 prepared by heating(A) an oxazol-5-one of formula